The document summarizes a capstone project on the effect of word variability on lexical decision task performance. It includes an introduction discussing the study being reviewed, literature reviewing critiques of that study related to sample size and confounding variables. The research objective and hypotheses aim to address these critiques by examining effects of language understanding and word variability on reaction time in lexical decision tasks. The method section outlines the participant demographics and materials used, including word lists varying in frequency and variability. The results section finds no significant effects of language understanding but significant effects of word variability on reaction time. Finally, the conclusion discusses key findings and limitations of the original study.

1. PSY499 PSYCHOLOGY
CAPSTONE PROJECT
Project title:The Effect ofWordVariability on the Lexical
DecisionTask: A Review

2. SCOPE
 Introduction
 Literature review
 Research objective & hypothesis
 Method
 Results
 Discussion & conclusion
 Q&A

3. LET’S DO A SIMPLE QUIZ!
Is this a word?
ZARF

4. How about this?
SLEEVE

5. ZARF = SLEEVE
Zarf /zarf/ [n]: a small, metal holder, used in
the Levant to hold a cup of hot coffee. (Collins
American English Dictionary)
A very valuable word in Scrabble ;)

6. INTRODUCTION
Azarbehi, Piercey and Joordens (2011):The effect of WordVariability on the Lexical
DecisionTask
 Word feature variability: Degree of spread of word feature in a presentation list
 Features manipulated
 Word frequency
 Orthographic neighbourhood
 Finding
 Interaction effect (word list type: words , non-words x stimulus type: homogenous,
heterogenous)
 Critiques
1. Small, uniformed sample
2. Possible confounding variables (word frequency and orthographic neighbourhood)

7. LITERATURE REVIEW
 Critique 1 : Small, uniformed sample
 Depth of writing script could influence performance on language tasks - > language
background of participant needs to be accounted for. (Liow & Poon, 1998)
 Interference effects might account for variance in Lexical Decision (Ehrich & Meuter,
2009)
 Critique 2: Possible confounding variables (word frequency and orthographic
neighbourhood)
 Some studies attempted to hold other word features constant (Connine, Mullennix,
Shernoff, &Yelen, 1990; Niendenthal, Halberstadt & Setterlund, 1997)

8. RESEARCH OBJECTIVE AND HYPOTHESIS
Research Objective
 To extend Azarbehi, Piercey and Joordens’ (2011) study by examining effects of language
understanding and word feature variability on LDT performance
Hypothesis
H1: Limited participant sample -> difference in ReactionTime (RT) in LDT performance
based on language understanding (Phonographic, Logographic).
H2: If word feature variability (in terms of word frequency) affect LDT performance ->
difference between RT taken to respond to HighVariability and LowVariability words.
H3: Participant’s language understanding affects the word feature variability on RT in the
LDT -> Interaction effect (language understanding x word feature variability).

9. METHOD
Participants • 185 Undergraduate students taking PSY107 - Introduction to Psychology 1
• Male – 72 (38.9%) Female – 113 (61.1%)
• No spectacles – 67 (36.2%) Spectacles - 118 (63.8%)
Materials • Javascript web based study using Qualtrics
• Word list - 10 words and 10 non-words, 5-7 letters long, number of syllables
was controlled.
Word frequency – obtained from Kucera and Francis (1967) word frequency
index
High Frequency - LowVariability (HF-LV) – 201-246 (SD 13.09),
orthographic neighbourhood 0
Low Frequency - LowVariability (LF-LV) - 1 -31 (SD 10.47), orthographic
neighbourhood 0
HighVariability (HV) - 1 -244 (SD 115.25), orthographic neighbourhood 0

10. METHOD
Procedure • Word lists are created with the following
parameters considered: Orthographic
structure, Orthographic Neighbourhood,
Phonological Structure and Phonological
Neighbourhood.
• Random assignment ( 49 – HF-LV, 86 –
LF-LV,50 – HV)
• Stimuli presented with black letters on
white black ground
• ‘z’ button – word, ‘/’ – non word
• 1 practice block (5 words, 5 non-words) –
presented sequentially
• 1 experimental block (10 words, 10 non-
words) – presented randomly

11. RESULTS
 No significant main effect on language understanding F(1,179)=
0.17, p >.05. (H1 not supported)
 Significant main effect on word feature variability F(2,179) =
3.32, p <.05. (H2 supported)
 No significant interaction between language understanding and
word feature variability, F(2,179) = 0.36, p >.05 . (H3 not
supported)

12. RESULTS
0
0.2
0.4
0.6
0.8
1
High Frequency - Low
Variability
Low Frequency - Low
Variability
High Variability
MeanRT(mSec)
Mean ReactionTimes (in mSec) forThreeTypes of
Word FeatureVariability: Means and Standard
Deviations
Post hoc analyses usingTukey HSD test - RT for HF-LV words
was significantly lower than RT for LF-LV words (p <.05).

13. DISCUSSION & CONCLUSION
Key Findings
 Participant’s perception of language understanding – did not affect
LDT performance for RT.
 Varying high/low word frequency in presentation list did not affect
LDT performance for RT.
Conclusion
 Perception of language understanding might not play as much as an
important role in LDT performance as proposed.
 Possible confounds exist in Azarbehi et al.’s (2011) study design.

14. REFERENCES
Azarbehi, R., Piercey, C. D., & Joordens, S. (2011).The effects of word variability on the
Lexical DecisionTask. North American Journal of Psychology, 13(3), 427–434.
Connine, C. M., Mullennix, J., Shernoff, E., &Yelen, J. (1990).Word familiarity and
frequency in visual and auditory word recognition. Journal of Experimental
Psychology. Learning, Memory, and Cognition, 16(6), 1084–1096.
Ehrich, J. F., & Meuter, R. F. I. (2009). Acquiring an Artificial Logographic. Journal of Cross-
Cultural Psychology, 711–745. http://doi.org/10.1177/0022022109338624
Liow, S. J. R., & Poon, K. K. L. (1998). Phonological awareness in multilingual Chinese
children, 19, 339–362.
Niendenthal, P. M., Halberstadt, J. B., & Setterlund, M. B. (1997). Being happy and seeing
“happy”: Emotional state mediates visual word recognition. Cognition & Emotion,
11, 403–432.

15. Q&A